Macroscopic and stereomicroscopic comparison of hacking trauma of bones before and after carbonization.

This experimental study examined lesions produced by a hatchet on pig femurs before and after carbonization. A total of 30 lesions were produced and analyzed using stereomicroscopy and then reexamined after carbonization. Not only was the sharp-blunt mechanism of the hacking trauma (V-shape, regularity of one edge, irregularity of the other edge, upraising, lateral pushing back, fossae dug laterally to the edge) still recognizable after carbonization; in some instances, the carbonization actually enhanced the features observed. Carbonization also did not significantly alter the measurements of the lesions. Carbonization tends to alter the structure of the bone especially in areas weakened by the blunt trauma.

Between blunt, sharp and hacking trauma: Observing the characteristics of pickaxe injuries.

Pickaxe injuries have never been thoroughly investigated in forensic science. This case, involving the fatal wounding of a 28-year-old individual by pickaxe blows to the head, abdomen, and hand, highlights the unique injury patterns associated with such an instrument. The injuries observed in the frontal skull exhibited characteristics akin to typical chop wounds, while those on the parietal skull bore similarities to blunt force trauma. The pickaxe penetrated the hands and the abdomen, with the depth of penetration directly correlating to the force applied. Consequently, pickaxe injuries can be considered a hybrid of different injury mechanisms, a fact that should be carefully considered in forensic analysis.

Microscopic analysis of cut mark characteristics from chopping/hacking tools.

Evaluating sharp force trauma (SFT) injuries to bone inflicted by a larger class of chopping/hacking tools (i.e., swords, axes, hatchets, machetes, and cleavers) is a growing area within the field of forensics. Previous studies have demonstrated promise regarding tool differentiation through the utilization of microscopic cut mark characteristics. However, this is an area that warrants additional investigation as there has yet to be a comprehensive study that incorporates the majority of these microscopic chopping/hacking cut mark characteristics into one analysis. The purpose of the current research was to analyze a large sample of microscopic cut mark characteristics derived from the current chopping/hacking literature to determine if differentiation of tool type could be made based on the microscopic cut mark characteristics. An additional goal of the current research is to develop standardization guidelines for the assessment of cut marks, focusing on a comprehensive suite of microscopic cut mark characteristics commonly observed in the existing literature. The skeletal sample for the current research was derived from a previous macroscopic cut mark characteristic experiment where trauma was inflicted to 20 partially fleshed domestic pig (Sus scrofa domesticus) limbs utilizing four chopping/hacking tools (i.e., axe, hatchet, machete, and cleaver) as well as a large carving knife for comparison. Cut marks were evaluated for 15 microscopic cut mark characteristics to assess statistical significance. Utilizing a chi-square analysis, nine of the 15 microscopic cut mark characteristics demonstrated statistically significant differences in relation to the tool utilized, indicating moderate to relatively strong effect sizes. For example, it should be possible to use a combination of microscopic cut mark characteristics to potentially indicate which chopping/hacking tool inflicted trauma when analyzing bones. In particular, examining the characteristics such as regularity of the cut mark edges along with the occurrence of uprising, fossae/depressions, and microscopic fractures can suggest or exclude tool class within forensic contexts.

Examination of Hacking and Blunt Force Skeletal Trauma.

Hacking trauma is prevalent in forensic cases involving genocide and dismemberment, but research into the identification of this type of trauma is lacking. The present study examines characteristics of hacking and blunt force skeletal trauma in order to determine if there is a point at which blunt force trauma becomes distinguishable from hacking trauma. Ten implements with a range of blade angles (i.e., the striking surface of the implement) were used in conjunction with a controlled-force hacking device to impact 100 limb bones of white-tailed deer (Odocoileus virginianus). Observations of the trauma included the occurrence and degree of fragmentation, the entrance widths of the impacts, and composite scores of six hacking characteristics, especially the distinctive V-shaped kerf. ANOVA tests and regression analyses were used to assess the relationships between these characteristics and the blade angles. A significant relationship (p-value = 0.011) was found between the composite hacking scores and the blade angles, indicating that blunt force and hacking trauma can be distinguished. The entrance widths of the impacts exhibited a significant relationship with the blade angles (p-value = 0.037). There was also a significant relationship between the visibility of a V-shaped kerf in the bones (p-value = 0.003), with visibility decreasing around the 60° blade angle. These data should assist in establishing guidelines to differentiate hacking and blunt force skeletal trauma in cases where the implement is on a spectrum between sharp and blunt.